221121021001 has 8 divisors (see below), whose sum is σ = 221839759944. Its totient is φ = 220402416000.

The previous prime is 221121020971. The next prime is 221121021029. The reversal of 221121021001 is 100120121122.

It can be written as a sum of positive squares in 4 ways, for example, as 47994293776 + 173126727225 = 219076^2 + 416085^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221121021001 - 2¹⁷ = 221120889929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221121021041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4094491 + ... + 4148143.

It is an arithmetic number, because the mean of its divisors is an integer number (27729969993).

Almost surely, 2^221121021001 is an apocalyptic number.

It is an amenable number.

221121021001 is a deficient number, since it is larger than the sum of its proper divisors (718738943).

221121021001 is a wasteful number, since it uses less digits than its factorization.

221121021001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66971.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 221121021001 its reverse (100120121122), we get a palindrome (321241142123).

The spelling of 221121021001 in words is "two hundred twenty-one billion, one hundred twenty-one million, twenty-one thousand, one".